Water pass

#version 450

#include "compiled.inc"
#include "std/gbuffer.glsl"
#include "std/math.glsl"

uniform sampler2D gbufferD;
uniform sampler2D tex;
uniform sampler2D sbase;
uniform sampler2D sdetail;
uniform sampler2D sfoam;
#ifdef _Rad
uniform sampler2D senvmapRadiance;
#endif

uniform float time;
uniform vec3 eye;
uniform vec3 eyeLook;
uniform vec2 cameraProj;
uniform vec3 ld;
uniform float envmapStrength;

in vec2 texCoord;
in vec3 viewRay;
out vec4 fragColor;

void main() {

    float gdepth = textureLod(gbufferD, texCoord, 0.0).r * 2.0 - 1.0;
    if (gdepth == 1.0) {
        fragColor = vec4(0.0);
        return;
    }

    // Eye below water
    if (eye.z < waterLevel) {
        fragColor = vec4(0.0);
        return;
    }

    // Displace surface
    vec3 vray = normalize(viewRay);
    vec3 p = getPos(eye, eyeLook, vray, gdepth, cameraProj);
    float speed = time * 2.0 * waterSpeed;
    p.z += sin(p.x * 10.0 / waterDisplace + speed) * cos(p.y * 10.0 / waterDisplace + speed) / 50.0 * waterDisplace;

    // Above water
    if (p.z > waterLevel) {
        fragColor = vec4(0.0);
        return;
    }

    // Hit plane to determine uvs
    vec3 v = normalize(eye - p.xyz);
    float t = -(dot(eye, vec3(0.0, 0.0, 1.0)) - waterLevel) / dot(v, vec3(0.0, 0.0, 1.0));
    vec3 hit = eye + t * v;
    hit.xy *= waterFreq;
    hit.z += waterLevel;

    // Sample normal maps
    vec2 tcnor0 = hit.xy / 3.0;
    vec3 n0 = textureLod(sdetail, tcnor0 + vec2(speed / 60.0, speed / 120.0), 0.0).rgb;

    vec2 tcnor1 = hit.xy / 6.0 + n0.xy / 20.0;
    vec3 n1 = textureLod(sbase, tcnor1 + vec2(speed / 40.0, speed / 80.0), 0.0).rgb;
    vec3 n2 = normalize(((n1 + n0) / 2.0) * 2.0 - 1.0);

    float ddepth = textureLod(gbufferD, texCoord + (n2.xy * n2.z) / 40.0, 0.0).r * 2.0 - 1.0;
    vec3 p2 = getPos(eye, eyeLook, vray, ddepth, cameraProj);
    vec2 tc = p2.z > waterLevel ? texCoord : texCoord + (n2.xy * n2.z) / 30.0 * waterRefract;

    // Light
    float fresnel = 1.0 - max(dot(n2, v), 0.0);
    fresnel = pow(fresnel, 30.0) * 0.45;
    vec3 r = reflect(-v, n2);
    #ifdef _Rad
    vec3 reflected =  textureLod(senvmapRadiance, envMapEquirect(r), 0).rgb;
    #else
    const vec3 reflected = vec3(0.5);
    #endif
    vec3 refracted = textureLod(tex, tc, 0.0).rgb;
    fragColor.rgb = mix(refracted, reflected, fresnel * waterReflect);
    fragColor.rgb *= waterColor;
    fragColor.rgb += clamp(pow(max(dot(r, ld), 0.0), 200.0) * (200.0 + 8.0) / (PI * 8.0), 0.0, 2.0);
    fragColor.rgb *= 1.0 - (clamp(-(p.z - waterLevel) * waterDensity, 0.0, 0.9));
    fragColor.a = clamp(abs(p.z - waterLevel) * 5.0, 0.0, 1.0);

    // Foam
    float fd = abs(p.z - waterLevel);
    if (fd < 0.1) {
        // Based on foam by Owen Deery
        // http://fire-face.com/personal/water
        vec3 foamMask0 = textureLod(sfoam, tcnor0 * 10, 0.0).rgb;
        vec3 foamMask1 = textureLod(sfoam, tcnor1 * 11, 0.0).rgb;
        vec3 foam = vec3(1.0) - foamMask0.rrr - foamMask1.bbb;
        float fac = 1.0 - (fd * (1.0 / 0.1));
        fragColor.rgb = mix(fragColor.rgb, clamp(foam, 0.0, 1.0), clamp(fac, 0.0, 1.0));
    }
}